Many methods of fabricating multi-story buildings exist. Traditionally, multi-story buildings have been fabricated upward from the ground, wherein fabrication begins on a ground level by attaching higher elevation structural elements on top of previously assembled lower structural elements to fabricate the building in upward direction, i.e., from bottom up. This method requires that the structural elements be lifted by a crane and connected in situ at elevation. This is particularly timely and costly when fabricating tall buildings.
One fabrication method includes fabricating a vertical support core of the building, which is designed to carry all structural loads of the building. The floor plates, including the roof structure surrounding a vertical support core, are fabricated around the base of the vertical support core at ground level, lifted vertically into place with strand jacks located on top of the vertical support core, and then connected to the vertical support core. In this matter, the roof structure surrounding the vertical support core is assembled at ground level, lifted to its final elevation, and then attached to the vertical support core. After the roof structure is attached to the vertical support core, the top floor plate is assembled at ground level, lifted to its final elevation, and then attached to the vertical support core. Subsequent floor plates are assembled and attached to the vertical support core in the same manner in a descending order. By so doing, the roof and the floor plates of the building are fabricated from top down.
The roof and floor plates may include cantilevered portions that extend from the vertical support core. Design features to minimize deflection of the roof and floor plates at the outer periphery of each floor plate may include increasing depth of framing members of the floor plates, which can affect floor height, building height, and material cost.